Improved algebraic cryptanalysis of QUAD, Bivium and Trivium via graph partitioning on equation systems

We present a novel approach for preprocessing systems of polynomial equations via graph partitioning. The variable-sharing graph of a system of polynomial equations is defined. If such graph is disconnected, then the corresponding system of equations can be split into smaller ones that can be solved individually. This can provide a tremendous speed-up in computing the solution to the system, but is unlikely to occur either randomly or in applications. However, by deleting certain vertices on the graph, the variable-sharing graph could be disconnected in a balanced fashion, and in turn the system of polynomial equations would be separated into smaller systems of near-equal sizes. In graph theory terms, this process is equivalent to finding balanced vertex partitions with minimum-weight vertex separators. The techniques of finding these vertex partitions are discussed, and experiments are performed to evaluate its practicality for general graphs and systems of polynomial equations. Applications of this approach in algebraic cryptanalysis on symmetric ciphers are presented: For the QUAD family of stream ciphers, we show how a malicious party can manufacture conforming systems that can be easily broken. For the stream ciphers Bivium and Trivium, we nachieve significant speedups in algebraic attacks against them, mainly in a partial key guess scenario. In each of these cases, the systems of polynomial equations involved are well-suited to our graph partitioning method. These results may open a new avenue for evaluating the security of symmetric ciphers against algebraic attacks.

Digital rights management

Digital rights management allows information owners to control the use and dissemination of electronic documents via a machine-readable licence. Documents are distributed in a protected form such that they may only be used with trusted environments, and only in accordance with terms and conditions stated in the licence. Digital rights management has found uses in protecting copyrighted audio-visual productions, private personal information, and companies' trade secrets and intellectual property. This chapter describes a general model of digital rights management together with the technologies used to implement each component of a digital rights management system, and desribes how digital rights management can be applied to secure the distribution of electronic information in a variety of contexts.

Speech recognition using ad-hoc microphone arrays

While close talking microphones give the best signal quality and produce the highest accuracy from current Automatic Speech Recognition (ASR) systems, the speech signal enhanced by microphone array has been shown to be an effective alternative in a noisy environment. The use of microphone arrays in contrast to close talking microphones alleviates the feeling of discomfort and distraction to the user. For this reason, microphone arrays are popular and have been used in a wide range of applications such as teleconferencing, hearing aids, speaker tracking, and as the front-end to speech recognition systems. With advances in sensor and sensor network technology, there is considerable potential for applications that employ ad-hoc networks of microphone-equipped devices collaboratively as a virtual microphone array. By allowing such devices to be distributed throughout the users’ environment, the microphone positions are no longer constrained to traditional fixed geometrical arrangements. This flexibility in the means of data acquisition allows different audio scenes to be captured to give a complete picture of the working environment. In such ad-hoc deployment of microphone sensors, however, the lack of information about the location of devices and active speakers poses technical challenges for array signal processing algorithms which must be addressed to allow deployment in real-world applications. While not an ad-hoc sensor network, conditions approaching this have in effect been imposed in recent National Institute of Standards and Technology (NIST) ASR evaluations on distant microphone recordings of meetings. The NIST evaluation data comes from multiple sites, each with different and often loosely specified distant microphone configurations. This research investigates how microphone array methods can be applied for ad-hoc microphone arrays. A particular focus is on devising methods that are robust to unknown microphone placements in order to improve the overall speech quality and recognition performance provided by the beamforming algorithms. In ad-hoc situations, microphone positions and likely source locations are not known and beamforming must be achieved blindly. There are two general approaches that can be employed to blindly estimate the steering vector for beamforming. The first is direct estimation without regard to the microphone and source locations. An alternative approach is instead to first determine the unknown microphone positions through array calibration methods and then to use the traditional geometrical formulation for the steering vector. Following these two major approaches investigated in this thesis, a novel clustered approach which includes clustering the microphones and selecting the clusters based on their proximity to the speaker is proposed. Novel experiments are conducted to demonstrate that the proposed method to automatically select clusters of microphones (ie, a subarray), closely located both to each other and to the desired speech source, may in fact provide a more robust speech enhancement and recognition than the full array could.

Accounting information systems in a centrally planned economy : the case of the General Company for Pipelines (GCP)

The paper has a twofold purpose. First it highlights the importance of accounting information in the economic development of developing countries, with a particular focus on the nation of Libya. Secondly, using the case of Libya's General Company for Pipelines (GCP), it demonstrates that the use of accounting information to achieve economic development goals is determined to a large extent by the political/ideological setting in which it is generated. The study is based on a literature review and archival research, reinforced by a qualitative case study comprised of interviews, attendance at meetings and a study of internal documents. A study of The General Company for Pipelines (GCP) revealed that frequent politically driven changes in the structure and number of popular congresses and committees severely limited the use of accounting information, relegating it to a formal role. In consequence, accounting information had litle effect on stimulating economic development in Libya. This study focuses on one case study which does limit generalisability. However, it also suggests fruitful research areas considering the historic factors which have determined the accounting role in developing and planned economies. By providing insights about social factors which have determined the use of accounting in a planned economy, this study has implications for similar economies as they move towards a more globalised mode of operations which enhance the role of accounting in meeting economic development needs. If devleoping countries are to harness the potential of accounting aid in the achievement of their development plans, the social and political setting in which accounting has been conducted needs to be understood.

Parents’ self-efficacy, outcome expectations, and self-reported task performance when managing atopic dermatitis in children: Instrument reliability and validity

BACKGROUND: Support and education for parents faced with managing a child with atopic dermatitis is crucial to the success of current treatments. Interventions aiming to improve parent management of this condition are promising. Unfortunately, evaluation is hampered by lack of precise research tools to measure change. OBJECTIVES: To develop a suite of valid and reliable research instruments to appraise parents' self-efficacy for performing atopic dermatitis management tasks; outcome expectations of performing management tasks; and self-reported task performance in a community sample of parents of children with atopic dermatitis. METHODS: The Parents' Eczema Management Scale (PEMS) and the Parents' Outcome Expectations of Eczema Management Scale (POEEMS) were developed from an existing self-efficacy scale, the Parental Self-Efficacy with Eczema Care Index (PASECI). Each scale was presented in a single self-administered questionnaire, to measure self-efficacy, outcome expectations, and self-reported task performance related to managing child atopic dermatitis. Each was tested with a community sample of parents of children with atopic dermatitis, and psychometric evaluation of the scales' reliability and validity was conducted. SETTING AND PARTICIPANTS: A community-based convenience sample of 120 parents of children with atopic dermatitis completed the self-administered questionnaire. Participants were recruited through schools across Australia. RESULTS: Satisfactory internal consistency and test-retest reliability was demonstrated for all three scales. Construct validity was satisfactory, with positive relationships between self-efficacy for managing atopic dermatitis and general perceived self-efficacy; self-efficacy for managing atopic dermatitis and self-reported task performance; and self-efficacy for managing atopic dermatitis and outcome expectations. Factor analyses revealed two-factor structures for PEMS and PASECI alike, with both scales containing factors related to performing routine management tasks, and managing the child's symptoms and behaviour. Factor analysis was also applied to POEEMS resulting in a three-factor structure. Factors relating to independent management of atopic dermatitis by the parent, involving healthcare professionals in management, and involving the child in the management of atopic dermatitis were found. Parents' self-efficacy and outcome expectations had a significant influence on self-reported task performance. CONCLUSIONS: Findings suggest that PEMS and POEEMS are valid and reliable instruments worthy of further psychometric evaluation. Likewise, validity and reliability of PASECI was confirmed.

The stewardship paradigm : an enquiry into the ethical obligation associated with being in control of resorces

The resource allocation and utilization discourse is dominated by debates about rights particularly individual property rights and ownership. This is due largely to the philosophic foundations provided by Hobbes and Locke and adopted by Bentham. In our community, though, resources come not merely with rights embedded but also obligations. The relevant laws and equitable principles which give shape to our shared rights and obligations with respect to resources take cognizance not merely of the title to the resource (the proprietary right) but the particular context in which the right is exercised. Moral philosophy regarding resource utilisation has from ancient times taken cognizance of obligations but with ascendance of modernity, the agenda of moral philosophy regarding resources, has been dominated, at least since John Locke, by a preoccupation with property rights; the ethical obligations associated with resource management have been largely ignored. The particular social context has also been ignored. Exploring this applied ethical terrain regarding resource utilisation, this thesis: (1) Revisits the justifications for modem property rights (and in that the exclusion of obligations); (2) Identifies major deficiencies in these justifications and reasons for this; (3) Traces the concept of stewardship as understood in classical Greek writing and in the New Testament, and considers its application in the Patristic period and by Medieval and reformist writers, before turning to investigate its influence on legal and equitable concepts through to the current day; 4) Discusses the nature of the stewardship obligation,maps it and offers a schematic for applying the Stewardship Paradigm to problems arising in daily life; and, (5) Discusses the way in which the Stewardship Paradigm may be applied by, and assists in resolving issues arising from within four dominant philosophic world views: (a) Rawls' social contract theory; (b) Utilitarianism as discussed by Peter Singer; (c) Christianity with particular focus on the theology of Douglas Hall; (d) Feminism particularly as expressed in the ethics of care of Carol Gilligan; and, offers some more general comments about stewardship in the context of an ethically plural community.

Post-tensioning and its effect on multi-level formwork load distribution

Multi-level concrete buildings requrre substantial temporary formwork structures to support the slabs during construction. The primary function of this formwork is to safely disperse the applied loads so that the slab being constructed, or the portion of the permanent structure already constructed, is not overloaded. Multi-level formwork is a procedure in which a limited number of formwork and shoring sets are cycled up the building as construction progresses. In this process, each new slab is supported by a number of lower level slabs. The new slab load is, essentially, distributed to these supporting slabs in direct proportion to their relative stiffness. When a slab is post-tensioned using draped tendons, slab lift occurs as a portion of the slab self-weight is balanced. The formwork and shores supporting that slab are unloaded by an amount equivalent to the load balanced by the post-tensioning. This produces a load distribution inherently different from that of a conventionally reinforced slab. Through , theoretical modelling and extensive on-site shore load measurement, this research examines the effects of post-tensioning on multilevel formwork load distribution. The research demonstrates that the load distribution process for post-tensioned slabs allows for improvements to current construction practice. These enhancements include a shortening of the construction period; an improvement in the safety of multi-level form work operations; and a reduction in the quantity of form work materials required for a project. These enhancements are achieved through the general improvement in safety offered by post-tensioning during the various formwork operations. The research demonstrates that there is generally a significant improvement in the factors of safety over those for conventionally reinforced slabs. This improvement in the factor of safety occurs at all stages of the multi-level formwork operation. The general improvement in the factors of safety with post-tensioned slabs allows for a shortening of the slab construction cycle time. Further, the low level of load redistribution that occurs during the stripping operations makes post-tensioned slabs ideally suited to reshoring procedures. Provided the overall number of interconnected levels remains unaltered, it is possible to increase the number of reshored levels while reducing the number of undisturbed shoring levels without altering the factors of safety, thereby, reducing the overall quantity of formwork and shoring materials.

Development of a process for dealing with underutilised Queensland government properties with heritage significance

This thesis addresses the contemporary issue of the control, restoration and potential for reuse of State Government-owned heritage properties with commercial potential. It attempts to reconcile the sometimes competing interests of the range of stakeholders in such properties, particularly those seeking to maximise economic performance and return on one hand and community expectations for heritage preservation and exhibition on the other. The matters are approached principally from the Government's position as asset owner/manager. It includes research into a number of key elements - including statutory, physical and economic parameters and an analysis of the legitimate requirements of all stakeholders. The thesis also recognises the need for innovation in approach and for the careful structuring and pre-planning of proposals on a project-by-project basis. On the matter of innovation, four case studies are included in the thesis to exhibit some approaches and techniques that have already been employed in addressing these issues. From this research base, a series of deductions at both a macro and micro level are established and a model for a rational decision-making process for dealing with such projects is developed as a major outcome of the work. Finally, the general model is applied to a specific project, the currently unused Port Office heritage site in the Brisbane Central Business District.

Fiji pre-service primary teachers' understanding of physical science : a cultural perspective

Science and technology are promoted as major contributors to national development. Consequently, improved science education has been placed high on the agenda of tasks to be tackled in many developing countries, although progress has often been limited. In fact there have been claims that the enormous investment in teaching science in developing countries has basically failed, with many reports of how efforts to teach science in developing countries often result in rote learning of strange concepts, mere copying of factual information, and a general lack of understanding on the part of local students. These generalisations can be applied to science education in Fiji. Muralidhar (1989) has described a situation in which upper primary and middle school students in Fiji were given little opportunity to engage in practical work; an extremely didactic form of teacher exposition was the predominant method of instruction during science lessons. He concluded that amongst other things, teachers' limited understanding, particularly of aspects of physical science, resulted in their rigid adherence to the text book or the omission of certain activities or topics. Although many of the problems associated with science education in developing countries have been documented, few attempts have been made to understand how non-Western students might better learn science. This study addresses the issue of Fiji pre-service primary teachers' understanding of a key aspect of physical science, namely, matter and how it changes, and their responses to learning experiences based on a constructivist epistemology. Initial interviews were used to probe pre-service primary teachers' understanding of this domain of science. The data were analysed to identify students' alternative and scientific conceptions. These conceptions were then used to construct Concept Profile Inventories (CPI) which allowed for qualitative comparison of the concepts of the two ethnic groups who took part in the study. This phase of the study also provided some insight into the interaction of scientific information and traditional beliefs in non-Western societies. A quantitative comparison of the groups' conceptions was conducted using a Science Concept Survey instrument developed from the CPis. These data provided considerable insight into the aspects of matter where the pre-service teachers' understanding was particularly weak. On the basis of these preliminary findings, a six-week teaching program aimed at improving the students' understanding of matter was implemented in an experimental design with a group of students. The intervention involved elements of pedagogy such as the use of analogies and concept maps which were novel to most of those who took part. At the conclusion of the teaching programme, the learning outcomes of the experimental group were compared with those of a control group taught in a more traditional manner. These outcomes were assessed quantitatively by means of pre- and post-tests and a delayed post-test, and qualitatively using an interview protocol. The students' views on the various teaching strategies used with the experimental group were also sought. The findings indicate that in the domain of matter little variation exists in the alternative conceptions held by Fijian and Indian students suggesting that cultural influences may be minimal in their construction. Furthermore, the teaching strategies implemented with the experimental group of students, although largely derived from Western research, showed considerable promise in the context of Fiji, where they appeared to be effective in improving the understanding of students from different cultural backgrounds. These outcomes may be of significance to those involved in teacher education and curriculum development in other developing countries.

The design and testing of a daylighting device : optimising the energy and optical performance of Australian commercial buildings

The effective daylighting of multistorey commercial building interiors poses an interesting problem for designers in Australia’s tropical and subtropical context. Given that a building exterior receives adequate sun and skylight as dictated by location-specific factors such as weather, siting and external obstructions; then the availability of daylight throughout its interior is dependant on certain building characteristics: the distance from a window façade (room depth), ceiling or window head height, window size and the visible transmittance of daylighting apertures. The daylighting of general stock, multistorey commercial buildings is made difficult by their design limitations with respect to some of these characteristics. The admission of daylight to these interiors is usually exclusively by vertical windows. Using conventional glazing, such windows can only admit sun and skylight to a depth of approximately 2 times the window height. This penetration depth is typically much less than the depth of the office interiors, so that core areas of these buildings receive little or no daylight. This issue is particularly relevant where deep, open plan office layouts prevail. The resulting interior daylight pattern is a relatively narrow perimeter zone bathed in (sometimes too intense) light, contrasted with a poorly daylit core zone. The broad luminance range this may present to a building occupant’s visual field can be a source of discomfort glare. Furthermore, the need in most tropical and subtropical regions to restrict solar heat gains to building interiors for much of the year has resulted in the widespread use of heavily tinted or reflective glazing on commercial building façades. This strategy reduces the amount of solar radiation admitted to the interior, thereby decreasing daylight levels proportionately throughout. However this technique does little to improve the way light is distributed throughout the office space. Where clear skies dominate weather conditions, at different times of day or year direct sunlight may pass unobstructed through vertical windows causing disability or discomfort glare for building occupants and as such, its admission to an interior must be appropriately controlled. Any daylighting system to be applied to multistorey commercial buildings must consider these design obstacles, and attempt to improve the distribution of daylight throughout these deep, sidelit office spaces without causing glare conditions. The research described in this thesis delineates first the design optimisation and then the actual prototyping and manufacture process of a daylighting device to be applied to such multistorey buildings in tropical and subtropical environments.